Albert Schweitzer has called Johann Arndt the " the prophet of interior Protestantism." This great German Lutheran mystic and follower of Melanchthon aroused Calvinist hostility by his spirituality of Christ in the heart of man. He was deposed as pastor of Bedeborn for refusing to abide by the orders of his Calvinist duke. Inspired by Bernard of Clairvaux, Angela of Foligno, John Tauler and Thomas a Kempis, he later came to be venerated by the Pietists. True Christianity is his principal mystical work and one of the most important in the Protestant tradition. He published the first book of this work, which is presented here, in 1605. He added three other books at a later date and two more were appended posthumously. Cover photography by Paul Spremulli